The present invention relates to a liquid crystal illumination device, a head up display, and an illumination method that illuminate a liquid crystal panel.
A liquid crystal illumination device guiding light projected from a light source to a liquid crystal panel side by a light guide unit, returning the light to the light source by a reflection member arranged on an exit side of the light guide unit, and use the light as recycled light is known (see Japanese Unexamined Patent Application Publication No. 2009-003444). On an entrance side of the light guide unit, an opening is formed correspondingly to the light source, and a reflective plate reflecting recycled light to the liquid crystal panel side is provided.